This invention relates to a gate motion mechanism for continuously performing a combination of two or more rectilineal motions as, for example, drawing an inverted letter "U".
Automatized devices for setting proper parts on workpieces to be machined include the gate motion mechanism. As shown typically in FIG. 1, the conventional mechanism has an arm 1 carrying a chuck 2 and a pair of jaws 2a thereunder. An inverted U-shaped gate motion of the arm 1, as indicated by arrows 6, enables one of parts 4 held in a row on a part chute 3 to be picked up by the jaws 2a and set in a corresponding dent of work 5.
It is known in the art that the mechanism for forcing such gate motion is of a construction as illustrated in FIG. 2. It comprises a shaft 10 to be rotated by a drive not shown, a cross feed cam 11 and a vertical feed cam 12 both of which are fixedly mounted on the shaft for rotation therewith, and levers 13, 14 slidable, respectively, along cam grooves 11a, 12a of the cams to transmit certain motions to guide rods 15 and a cross slide 17. Since the movement of the guide rods 15 is guided by the cross slide 17 supported by a slide bar 16, a head 18 secured to the front ends of the guide rods 15 makes a given gate motion. The cross feed cam 11 forces the lever 13 to move the guide rods 15 backward and forward, while the vertical feed cam 12 forces the lever 14 to move the cross slide 17 upward and downward. Consequently, the head 18 combines the back-and-forth motion of the guide rods 15 and the up-down motion of the cross slide 17 into a gate motion reciprocatingly along the full and broken lines indicated by arrows 19, 19a.
The known gate motion mechanism requires cams, levers, and other associated parts all in pairs. This complicates the construction and makes the arrangement large in size, occupying a great deal of space.